The use of the rigid endoscope in trans-sphenoidal pituitary surgery

Endoscopic transphenoidal pituitary surgery with real-time intraoperative magnetic resonance imaging

BACKGROUND

The aim of this study was to report and show the technique, results, and complications of combined endoscopic and intraoperative magnetic resonance imaging (IMRI) surgical treatment of pituitary disease from both a technical and a surgical perspective.

METHODS

We performed a retrospective chart review of 10 endoscopic, endonasal resections of 10 pituitary macroadenomas using the Polestar N-10 IMRI system in a tertiary health care facility. The patient demographics, tumor measurements, and postoperative symptoms and complications were assessed. The effect of the magnetic field on the video screen, the image quality of the IMRI images, and IMRI detection of residual tumor were evaluated also.

RESULTS

IMRI images were obtained in all cases and were of sufficiently high quality to indicate adequate decompression of the optic chiasm and the removal of all suprasellar tumor. However, there was significant distortion of the video monitor regardless of the viewing angle. This was overcome with a wall-mounted plasma screen. Residual tumor was found with IMRI and resected endoscopically in three cases. In two other cases, suspected residual tumor on IMRI was examined endoscopically and found to be a normal postoperative change. In two cases no tumor was seen on the IMRI. Five patients who had preoperative progressive visual loss preoperatively improved postresection and two patients who had increased insulin growth factor 1 preoperatively normalized postoperatively. No delayed cerebrospinal fluid leaks or any other complications occurred.

CONCLUSION

Combining intraoperative endoscopy and IMRI is an effective surgical modality for pituitary surgery. Each technology provides complimentary information, which can assist the surgeon in safely maximizing the extent of resection.

Endoscopic transsphenoidal surgery: stone-in-the-pond effect

THE TRANSSPHENOIDAL MIDLINE route represents the standard approach to the pituitary and sellar area and is used for more than 95% of surgical indications in this region. It is the least traumatic route to the sella turcica, it avoids brain retraction, and it provides excellent visualization of the pituitary gland and lesions related to that structure. The technique has essentially replaced craniotomy and has been used by every pituitary neurosurgeon, representing the "gold standard" of the transsphenoidal approach to the sellar region for more than 30 years. The introduction of endoscopic techniques has produced a "stone-in-the-pond" effect, influencing the relatively peaceful neurosurgical environment. The brilliant increased vision of the surgical target offered by the endoscope can allow more effective removal of the lesion, followed by superior clinical results and a reduction in the incidence of complications. Endoscopy contributes to better and more contemporary knowledge of the possibilities of the transsphenoidal approach, thus increasing the extended approaches, not only for the pituitary area. Whether or not the transsphenoidal approach should be performed with the use of the microscope or the endoscope is finally discussed.

Endoscopic Transsphenoidal Pituitary Surgery with Intraoperative Magnetic Resonance Imaging

OBJECTIVE:

The two most recent significant advances in pituitary surgery have been the endonasal endoscopic approach and intraoperative magnetic resonance imaging (IMRI). Each provides improved visualization of intra- and parasellar anatomy with the goal of attaining a complete resection. The combination of the two techniques has not been previously reported in the literature.

METHODS:

We performed endoscopic, endonasal resection of pituitary macroadenomas in 15 patients using the Polestar N-10 (0.12T) IMRI (Odin Medical Technologies, Inc., Newton, MA). Eleven patients had nonfunctioning tumors, three had acromegaly, and one had a medication-resistant prolactinoma. The effect of the magnetic field on the cathode ray tube screen and the image quality of the IMRI images were assessed. The presence of residual tumor on IMRI was noted and then re-examined with the endoscope.

RESULTS:

Although the Polestar N-10 is a low Tesla magnet, the IMRI caused significant distortion of the cathode ray tube screen regardless of the viewing angle. This was overcome with the use of a wall-mounted plasma screen. IMRI images were obtained in all cases and were of sufficiently high quality to demonstrate adequate decompression of the optic chiasm and the removal of all suprasellar tumor. In three cases, residual tumor was found with IMRI that was resected endoscopically before the completion of surgery. In four other cases, potential residual tumor was examined endoscopically and found to be normal postoperative change. In eight cases no residual intrasellar tumor was seen on the IMRI. Preresection visual deficits improved in all cases and the insulin-like growth factor levels normalized in two of three cases. There were no delayed cerebrospinal fluid leaks.

CONCLUSION:

Combining intraoperative endoscopy and IMRI is feasible and distortion of the cathode ray tube screen can be overcome with the use of either a plasma or liquid crystal display screen. Each technology provides complementary information, which can assist the surgeon in safely maximizing the extent of resection. In this small series using a low-field magnet, rates of residual tumor following endoscopic trans-sphenoidal surgery were less than have been reported following microscope-based transsphenoidal surgery.

Brief history of endoscopic transsphenoidal surgery--from Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery

Since its inception, one of the major issues in transsphenoidal surgery has been the adequate visualization of anatomical structures. As transsphenoidal surgery evolved, technical advancements improved the surgical view of the operative field and the orientation. The operating microscope replaced Cushing's headlight and Dott's lighted speculum retractor, and fluoroscopy provided intraoperative imaging. These advances led to the modern concept of microsurgical transsphenoidal procedures in the early 1970s. For the past 30 years the endoscope has been used for the treatment of diseases of the sinus and, more recently, in the surgical treatment of pituitary tumors. The collaboration between neurological and otorhinolaryngological surgeons has led to the development of novel surgical procedures for the treatment of various pathological conditions in the skull base. In this paper the authors review the history of the endoscope--its technical development and its application--from the first endoscope described by Philipp Bozzini to the First World Congress of Endoscopic Skull Base Surgery held in 2005 in Pittsburgh, Pennsylvania. Specifically, in this review the history of endoscopy and its application in endonasal neurosurgery are presented.

Endoscopic transnasal transsphenoidal pituitary surgery--comparison with the traditional sublabial transseptal approach

The technique of endoscopic transnasal, nontransseptal, transsphenoidal pituitary surgery is gaining increasing popularity. Many pituitary surgical teams consider it the procedure of choice. It provides a rapid and safe approach to the sella turcica. Within the sella turcica, the endoscopes give the surgeon the ability to inspect around the corner and to remove residual tumor. The procedure avoids the complications related to the sublabial transeptal approach. Hospital stay is shorter.

Safety of Minimally Invasive Pituitary Surgery (MIPS) Compared with a Traditional Approach

INTRODUCTION

Transsphenoidal hypophysectomy is becoming progressively less invasive. Recent endoscopic techniques avoid nasal or intraoral incisions, use of nasal speculums, and nasal packing. Several case series of endoscopic endonasal pituitary surgery have been reported, but relatively little data exists comparing complication rates to more traditional approaches. We compare the complications of our first 50 cases of endoscopic, minimally invasive pituitary surgery (MIPS) to our last 50 sublabial transseptal (SLTS) procedures.

STUDY DESIGN

Retrospective case control study.

METHODS

Fifty consecutive MIPS procedures and 50 consecutive SLTS procedures were reviewed retrospectively. Complication rates were analyzed and compared.

RESULTS

Total complications per patient (P = .005), postoperative epistaxis (P = .031), lip anesthesia (P = .013), and deviated septum (P = .028) occurred more often in the SLTS group. No significant difference was seen in cerebrospinal fluid leak, meningitis, ophthalmoplegia, visual acuity loss, diabetes insipidus, intracranial hemorrhage, or death. In the MIPS group, length of stay (P < .001), use of lumbar drainage (P = .007), and nasal packing (P < .001) were also significantly reduced.

CONCLUSIONS

Endoscopic endonasal pituitary surgery provides improved complication rates when compared with SLTS approaches. In addition, we note advantages of the MIPS approach, including reduced length of hospital stay and decreased use of lumbar drainage and nasal packing.

Endoscopy and Transsphenoidal Surgery

ENDOSCOPY OFFERS INTERNAL visualization of many different cavities of the human body, with its specific vision inside the anatomy, close to the target area. The view of the surgical field in transsphenoidal surgery had been obtained with the naked eye from its beginning in 1907 up to the introduction of the operating microscope by Jules Hardy in the 1960s, which represented a great advance in terms of magnification and illumination. In the past decade, modern rigid endoscopes, with their wider view near the relevant anatomy, have permitted minimally traumatic transsphenoidal procedures in and around the sellar area, thus representing a "new wave" in transsphenoidal history. An overview of the evolution of the endoscope as a visualizing and operating instrument particularly related to the transsphenoidal approach is presented here. The current possibilities of transsphenoidal endoscopy, with its related advantages and limitations, are presented.

[Trans-septal endoscopic approach of pituitary tumors]

The advances in endoscopic instruments have eased the approach to the sellar region through the nasal cavity. We carry out an analysis of the surgical results on 20 patients that underwent surgery for sellar tumours through a transeptal-transphenoidal approach in the last 2 years in our hospital. The average was 45.6 years old, and 75% were females. 30% of cases were pituitary adenomas and another 30% acromegaly, 25% Cushing's disease and 10% prolactinomas. No complications were encountered during surgery being the most common postoperative complications, diabetes insipida in two cases (10%) and CSF leak in one case. At present 2 patients are having hormonal treatment for panhypopituitarism. No patients developed a septal perforation, nasal deformity, epistaxis, meningitis, lip numbness or oronasal fistula. The rest did have good results noith no recurrence and hormonal values back to normal.

History of neuroendoscopy

Since the beginnings of medicine, physicians have sought minimally invasive ways to peer into body cavities. It is only in the last several decades that the promises of endoscopy have begun to be answered. What follows is a brief outline of the development of endoscopic technology and its application to the nervous system both for diagnostic and therapeutic procedures.

[Intranasal approaches for pituitary area tumors. Our experience]

Transsphenoidal approach is the most commonly employed surgical technique for the resection of pituitary tumors. We present our experience in the transnasal-transsphenoidal approach in 30 patients undergoing pituitary surgery from 1998 to 2002. Ten patients underwent surgery via a sublabial-transeptal-transsphenoidal approach, 15 patients via a transeptal-transsphenoidal approach and 5 patients via a pure endoscopic transnasal-transsphenoidal. The pathological study showed 29 pituitary adenomas and 1 Rathe's cleft cyst. We conclude that the pure endoscopic transnasal-transsphenoidal approach guided by a navigator-system is safest and more effective approach. We reserved the transeptal-transsphenoidal approach for cases with obstructive septal deflection and poor pneumatized sphenoid sinuses. We do not recommend the use of the sublabial-trans-sphenoidal approach.

Endoscopic approach to the pituitary lesions: contemporary method and review of the literature

The present status of endoscopic transsphenoidal surgery is introduced and reviewed. The difference between endoscopic and microscopic transsphenoidal surgery is explained and also the characteristics of the transnostril approach is mentioned. The advantages of endoscopic surgery are (1) good anatomical orientation with wider view, (2) tumors at the dead angle can be removed under the direct visualization, and (3) the patients can drink, eat and even brush their teeth just after surgery. Short hospital stay and even day-surgery could be possible when a patient is carefully selected. The disadvantages and the limitation of endoscopic surgery have been solved and improved with several new instruments and ideas. Moreover, we have made use of the surgical simulation with the three-dimensional (3-D) CT virtual navigation endoscopic image and the navigation system with the ENT application and the SureTrak of the Stealth Station. There is no need for head fixation with a Mayfield clamp or a C-arm intraoperative fluoroscopic image. This image guidance enabled a correct and smooth approach even in those patients with complicated and abnormal anatomical structures by prior surgery such as for sinusitis. The sellar floor can be safely and correctly opened even in patients with conchal type sphenoid sinus using a navigation system that helps to understand the locations of the cavernous sinus and the internal carotid arteries. The overall result by endoscopic transsphenoidal surgery is as good as or better than that by the traditional microscopic transsphenoidal surgery.

Comparison of endonasal endoscopic surgery and sublabial microsurgery for prolactinomas

BACKGROUND

Endonasal endoscopy is a promising minimally invasive surgery for the treatment of pituitary adenomas; it is also a good alternative to traditional sublabial microsurgery. In this study, we compared endoscopic surgery with microsurgery and evaluated both for their safety and effectiveness. We chose prolactinomas for study because their hormone and symptomatic changes facilitated the comparison.

METHODS

During the past five years, 44 randomized prolactinoma patients underwent pituitary adenomectomy. Group A (22 patients) underwent endonasal endoscopic surgery for prolactinomas. Group B (22 patients) underwent sublabial transsphenoidal microsurgery for prolactinomas.

RESULTS

In groups A and B, patients with prolactinoma exhibited significantly reduced postoperative prolactin levels, return of menstrual cycle, and relief of galactorrhea, (Wilcoxon signed rank test) (p < 0.001). But there were no statistically significant differences in the effectiveness of the procedures used in group A and group B. Visual improvement in cases of macroadenoma was satisfactory in both groups. Hospital stay in group A ranged from 2-5 days, with a mean of 3.2 days. Hospital stay in group B ranged from 4-8 days with a mean of 5.3 days. The hospital stay for group A patients was shorter (2.1 days) than for group B (Student t test, p < 0.05). The operative time was shorter by 1 hour in Group A (mean: 1.7 hours vs. mean: 2.7 hours, p < 0.05). There were fewer complications in group A (4.5%) than in group B (27%), p < 0.05.

CONCLUSIONS

The endoscopic era of pituitary surgery may be coming. Endonasal endoscopic surgery may have the same effectiveness as traditional microsurgery. However, endoscopic surgery may shorten hospital stay and operative time, and lead to fewer complications. It seems to be a good minimally invasive surgical technique for prolactinomas.

Minimally invasive endoscope-assisted endonasal trans-sphenoidal microsurgery for pituitary tumors: experience with 215 cases comparing with sublabial trans-sphenoidal approach

Recent advances in endoscopic surgery have developed an endonasal route suitable for pituitary surgery. The main goal of this article is to evaluate benefits of our endoscope-assisted endonasal trans-sphenoidal microsurgery for pituitary tumors in 215 consecutive cases. The pathological classifications of the 215 cases are as follows: 163 pituitary adenomas, 23 Rathke's cleft cysts, 17 craniopharyngiomas, and 12 others. The patients were surgically treated via the endonasal trans-sphenoidal approach using an operating microscope as the primary instrument for tumor resection. Endoscopes were used to complement the operating microscope in visualization. We compared the new approach to the sublabial trans-sphenoidal approach (197 cases) with respect to endocrinological outcomes and surgical complications. Our endonasal trans-sphenoidal approach was beneficial in eliminating the complications of lip numbness, which was often observed in patients undergoing sublabial surgery, and nasal septal perforation. In addition, endocrinological outcome comparable to those in the sublabial group was achieved in the endonasal group. We consider that the endoscope, which allows visualization of areas not seen with the operating microscope, should be used actively in conjunction with the operating microscope that provides three-dimensional visualization and is timesaving. Our surgical method for pituitary tumors provides good results with minimal invasion, by exploiting the advantages of a microscope and an endoscope.

Pituitary surgery

This article focuses on surgical indications, perioperative management, and endoscopic approaches for pituitary surgery. Also discussed are sinonasal, neurologic, and endocrine complications, which may include bleeding, sinusitis, and synechiae; cerebrospinal fluid leaks and bleeding; and diabetes insipidus and panhypopituitarism, respectively.

[Neuroendoscopic endonasal transseptal approach to the sellar region: study of 30 cases]

An endoscopic endonasal transsphenoidal approach to the sella was performed in 30 patients. The use of endoscope allowed close inspection and differentiation between tumor tissue and glandular remains, resulting in micro dissection of the tumor with maximum preservation of pituitary function. The angled view of the endoscope helps gross total removal of the tumor tissue, from the supra and para sellar extension. The endonasal transseptal endoscopic approach helps from dental problems, and lowers incidence of septal perforation, synechia, and crust formation. However the endoscopic approach has drawbacks. Its decreases the depth of field, needs constant manual control of the endoscope, and requires experience with the endoscope technique.

Historical movements in transsphenoidal surgery

Over the past century pituitary surgery has undergone multiple revolutions in surgical technique and technological advancements that have resulted in what is now recognized as modern transsphenoidal surgery. Although the procedure is well established in the current neurosurgical literature, the historical maze that led to its development continues to be of interest because it allows us to appreciate better the unique contributions made by the pioneers of the technique as well as the innovative spirit that continues to fuel neurosurgery. The early events in the history of transsphenoidal surgery have already been well documented. Therefore, the authors summarize the major early transitions along the timeline and then further describe more recent advancements in transsphenoidal surgery such as the surgical microscope, fluoroscopy, endoscopy, intraoperative neuroimaging, frameless image guidance, and radioimmunoassay. The story of these innovations is unique because each was developed as a response to certain needs of the surgeon. An understanding of these more recent contributions coupled with the early history provides a more complete perspective on modern transsphenoidal surgery.

Endoscopic transsphenoidal approach through a widened nasal cavity for pituitary lesions

We operated upon 12 patients with macroadenoma and two with Rathke's cleft cyst using an endoscope through a nasal speculum. Pure endoscopic endonasal transsphenoiolal approach (TSA) was performed in nine patients and endoscope-assisted microscopic endo nasal TSA in five. A thin-bladed nasal speculum was used to achieve a wide, almost midline, pathway without an incision at the septal mucosa. This made it possible to convert from the endoscopic to the microscopic approach and vice versa at any time during operation as the occasion demanded. In 10 of the 12 patients with macroadenoma, adenomas were removed totally and did not recur during the mean follow-up period of 24 months. Two adenomas could not be removed totally due to their invasiveness. In two of five patients who underwent endoscope-assisted microscopic TSA for macroadenoma, the endoscope could visualise residual tumour at blind corners after microscopic tumor removal. Two patients with Rathke's cleft cyst did not show recurrence. No patient showed sinonasal or endocrinological complications. Versatile use of the endoscope through a widened nasal cavity using a nasal speculum is a promising tool for the treatment of pituitary lesions.

Endoscopic transsphenoidal surgery

BACKGROUND

Endoscopic transsphenoidal surgery was developed under a minimally invasive surgical strategy. This endonasal transsphenoidal endoscopy eliminates a sublabial or transfixional incision, the use of a transsphenoidal retractor and any nasal packing.

MATERIALS AND METHOD

Reported are 160 patients who had undergone endoscopic transsphenoidal surgery from 1993 to 1999. Seventy were men and ninety women. Age ranged from 14 to 88 years (median 43 years). Among the 160 patients, 128 had pituitary adenomas, 9 had anterior fossa meningiomas, 7 had clival chordomas and 16 patients had other pathologies.

RESULTS

Among the 68 patients with hormone-none-secreting adenomas, 53 (78%) patients had gross total removal. Among the 35 patients with prolactinomas, 24 (71%) patients exhibited normalized prolactin levels postoperatively. Eleven (70%) patients among the 16 with Cushing's disease had normal postoperative cortisol levels. Among the 9 patients with acromegaly, 7 (78%) had normalized postoperative IGF-1 levels. Among the 9 patients with anterior cranial fossa meningiomas. 7 had gross total removal and 2 had subtotal removal. Among the 7 patients with clival chordomas, 5 had total removal and 2 had subtotal removal. One patient with a large calcified recurrent pituitary fibrosarcoma died postoperatively. Postoperative morbidities included cerebrospinal fluid (CSF) leak in 6%, meningitis in 1.2%, deterioration of anterior pituitary function in 11%, temporary diabetes insipidus in 4%, permanent diabetes insipidus in 3%, and sinusitis in 1.2%. Outpatient surgery was performed in 2 patients. One hundred and eleven patients (66%) stayed in the hospital only overnight. Postoperative discomfort was minimal.

CONCLUSION

Endoscopic endonasal transsphenoidal surgery in this series resulted with comparable surgical outcomes to conventional microscopic transsphenoidal surgery. Patients' quick recovery, short hospital stays, and minimal postoperative discomfort have been observed.

Hypophysis surgery with or without endoscopy

OBJECTIVE

Hardy's operation with microscope has long been the standard method for pituitary adenoma. But a new approach via the nasal cavity using an endoscope has been adopted recently. In this study, the postoperative outcome as well as the preoperative evaluation of endoscopic hypophysectomy and non-endoscopic one were compared at our faculty.

METHOD

We performed the non-endoscopic transnasal hypophysectomy on 18 patients and the endoscopic transnasal hypophysectomy on thirteen patients who had a pituitary lesions from February 1996 to October 1999. As to these patients the situations from preoperation through postoperation such as chief complaints, serum hormone level, final diagnosis, tumor size, as well as operating time or blood loss during the operation were discussed precisely. Then the merits and demerits of endoscopic hypophysectomy were discussed.

RESULT

Five PRL-producing adenoma, three GH-producing adenoma, nine non-functioning adenoma, and two ACTH or TSH-producing adenoma were included in this discussion as endoscopic group. The age of non-endoscopic group are from 23 to 73 (49.4 in average), and they include ten males and eight females. On the other hand three PRL-producing adenoma, two GH-producing adenoma, two non-functioning adenoma, and one Rathke's cyst were included in this discussion as endoscopic group. The age of endoscopic group are from 19 to 73 (49.1 in average), and they include seven males and six females. As to non-endopscopic group the blood loss during each operation is 568 ml and operating time is 256 min in average. For endoscopic group the blood loss is 296 ml and operating time is 234 min in average.

CONCLUSION

By microsurgery in the pituitary operation with endoscopy, the minimal invasive surgery becomes possible by reducing blood loss and shortening operating time. During the operation cooperation between neurosurgeon and ENT surgeon is indispensable in order to perform hypophysectomy smoothly. The development of optical better aids and operation instruments for endonasal hypophysectomy is desired in the future. The navigation system was more useful than X-ray fluoroscopy to obtain the detailed information.

Endoscopic-guided direct endonasal approach for pituitary surgery

BACKGROUND

Submucosal dissection of the nasal septum is often performed as part of the transseptal approach to the sella. To evaluate whether this submucosal dissection is a necessary component of this operation, we compared the morbidity of a direct transmucosal endonasal approach to that of the transseptal approach in patients undergoing pituitary surgery.

METHODS

Forty-one consecutive patients undergoing pituitary surgery from January 1996 to March 1999 were included in this study. The first 21 patients underwent the standard transseptal operation through either a sublabial or columellar incision. The latter 20 patients were operated on through an endoscopically guided, direct endonasal exposure, without any submucosal dissection of the nasal septum. The operative morbidity, the duration of surgery, and the length of hospitalization for each group were compared.

RESULTS

The sphenoid sinus exposure obtained through the endonasal route was comparable with the transseptal approach and was adequate for resection of most pituitary tumors. Although the morbidity of the two approaches was similar, patients undergoing the endonasal operation had less postoperative facial pain. Furthermore, the endonasal approach significantly decreased the length of the operation (116 minutes vs. 161 minutes, p = 0.002) and the duration of hospitalization (3.6 vs. 5.1 days, p = 0.003) as compared with the transseptal route.

CONCLUSIONS

Morbidity of the endonasal approach to the sphenoid sinus is comparable to that of a conventional transseptal approach. By eliminating the submucosal dissection, the endonasal approach reduces postoperative facial discomfort and decreases length of surgery and hospitalization.

Endoscopic pituitary surgery

Endoscopy has been adopted for transsphenoidal pituitary surgery. A rigid rod-lens endoscope, 4-mm in diameter and 18 cm in length, is used in replacement of the operating microscope. This endoscopic technique utilizes the patient's natural nasal air passage as a surgical corridor without a sublabial or nasal mucosal incision. The use of a transsphenoidal retractor is not necessary. Postoperative nasal packing is not required. The average length of a patient's hospital stay is overnight. Postoperative discomfort is minimal. An angled lens endoscope enables the surgeon to operate on tumors located in the suprasellar region under direct visualization. When the adoption of endoscopy in transsphenoidal pituitary surgery had demonstrated obvious advantages over conventional microscopic surgery, the use of this endoscopic endonasal technique has been expanded to include other skull base lesions at the anterior fossa skull base, cavernous sinus, clivus and clival posterior fossa. In this chapter, the author describes the evolution of this endoscopic transsphenoidal surgery, the pertinent sinonasal anatomy related to transsphenoidal endoscopy, the details of endoscopic endonasal transsphenoidal pituitary surgery, surgical approaches to the other skull base lesions, surgical results, and potential complications and their avoidance.

Preliminary comparison of the endoscopic transnasal vs the sublabial transseptal approach for clinically nonfunctioning pituitary macroadenomas

OBJECTIVE

To assess the advantages and disadvantages of an endoscopic transnasal approach to pituitary surgery for a select group of clinically nonfunctioning macroadenomas and to compare results of this approach with the sublabial transseptal approach at a single institution.

PATIENTS AND METHODS

We retrospectively reviewed the records of 26 patients with clinically nonfunctioning pituitary macroadenomas approached endoscopically and 44 matched control patients with the same tumors approached sublabially between January 1, 1995, and October 31, 1997.

RESULTS

At baseline, the groups were not significantly different for age, sex distribution, number of comorbid conditions, visual field defects, degree of anterior pituitary insufficiency, or preoperative assessment of tumor volume or invasiveness. Mean (SD) operative times were significantly reduced in the endoscopic group vs the sublabial group: 2.7 (0.7) hours vs 3.4 (0.9) hours (P < .001). Postoperative assessment of surgical resection and postoperative alterations of anterior pituitary function or visual fields were not significantly different between groups, and complication rates were similar in both groups.

CONCLUSION

This endoscopic transnasal approach to pituitary resection results in significantly shorter operative time without compromising the extent of tumor resection. The distinct disadvantage of this approach is an off-center view of the sella and a diminished working channel to the sella turcica. For these reasons, the endoscopic approach or its variation is an alternative to the sublabial approach but should be considered only by experienced pituitary neurosurgeons.

Approaches to the sellar and parasellar region: anatomic comparison of the microscope versus endoscope

OBJECTIVE

Traditionally, surgical approaches to the sellar region require the use of the operating microscope. Over the past decade endoscopic surgery has gained much popularity because of advances in optics and illumination. Endoscopic surgery of the sellar region has been performed successfully. The goal of the present study was to quantify the amount of exposure to the sellar and suprasellar region that the endoscope provides versus the microscope, with three different anterior approaches to the sellar region.

METHODS

The transethmoidal, endonasal-transsphenoidal, and sublabial-transsphenoidal approaches were performed on 14 formalin-fixed cadaver heads with a 0 degrees endoscope and repeated with the operative microscope. The distances of relevant surgical landmarks and the amount of exposure superior and anterior to the dorsum sella, as well as the lateral exposure, were measured. The mean distances were then used to calculate the volume of exposure for each of the approaches.

RESULTS

It was found that the endoscope provided greater view than the operating microscope in all three approaches. The difference was statistically significant using a paired Student t test and a signed-rank test (P<.001).

CONCLUSION

The authors believe that endoscopic surgery of the sellar region can be performed safely and effectively, while providing the surgeon with a view that is superior to that afforded by the operating microscope.

Endoscopic pituitary surgery: an in vivo model for transnasal transsphenoidal hypophysectomy

The transseptal transsphenoidal approach to surgical intervention of the pituitary gland has been described for decades. Its gradual acceptance as the standard of therapy is indicative of general trends toward less invasive means of managing intracranial surgical disease. The evolution of the technique has coincided with advances in medical technology, including the introductions of intraoperative fluoroscopy and operative microscopy. Current progress in the field of endoscopy promises to further this evolution: endoscopic telescopes and instruments have improved on the optical and technical limitations of the microscope and require an even less invasive approach to the sella. To test the benefits and limitations of the endoscope in performing transnasal transsphenoidal hypophysectomy in an in vivo model, we operated on two live anesthetized pigs using 4.0-mm 0- and 30-degree 18-cm long endoscopes. The long lengths of the pig snouts precluded a transnasal approach to the sella; however, we were able to use the endoscopes to explore the sphenoid sinus, sella turcica, and parasellar regions via a transoral exposure. Digital images of the relevant skull base anatomy were captured. The benefits and limitations of the technique were noted and compared with our experience with microscopy in transsphenoidal hypophysectomy in humans.

Intracranial endoscopy

The authors' intention is to reduce the invasiveness of intracranial procedures while avoiding traumatization of brain tissue, to decrease the risk of neurological and mental deficits. Intracranial endoscopy is a minimally invasive technique that provides rapid access to the target via small burr holes without the need for brain retraction. Craniotomy as well as microsurgical brain splitting and dissection can often be avoided. Furthermore, because obstructed cerebrospinal fluid pathways can be physiologically restored, the need for shunt placement is eliminated. The ventricular system and subarachnoid spaces provide ideal conditions for the use of an endoscope. Therefore, a variety of disorders, such as hydrocephalus, small intraventricular lesions, and arachnoid and parenchymal cysts can be effectively treated using endoscopic techniques. With the aid of special instruments, laser fibers, and bipolar diathermy, even highly vascularized lesions such as cavernomas may be treated. Moreover, during standard microsurgical procedures, the endoscopic view may provide valuable additional information ("looking around a corner") about the individual anatomy that is not visible with the microscope. In transsphenoidal pituitary surgery, transseptal dissection can be avoided if an endonasal approach is taken. In the depth of the intrasellar space, the extent of tumor removal can be more accurately controlled, especially in larger tumors with para- and suprasellar growth.

The combined use of endoscopes and computerized neuronavigation systems increases the accuracy of the approach and provides real-time control of the endoscope tip position and approach trajectory. In the future, the indications for neuroendoscopy will certainly expand with improved technical equipment.

A combined, minimally invasive transnasal approach to the sella turcica

The increasing use of endonasal techniques and a new 3-dimensional CT-guided imaging system have allowed us to develop a combined, minimally invasive endonasal approach to the pituitary gland. Thus far, more than 30 patients have undergone an endonasal transsphenoidal approach to the sella using a combined endoscopic approach, with additional selective use of the Instatrak CT-guided imaging system for real-time imaging. Our current technique involves obtaining a preoperative CT using a plastic head frame with registration markers. By using this head frame intraoperatively, real-time localization with CT images in axial, coronal, and sagittal planes can be performed. Using endoscopic techniques and a Papavero-Caspar speculum, the sella is exposed. A combined approach using endoscopes, the operating microscope, and real-time localization is undertaken to expose and resect tumors. We have encountered minimal associated complications in our series, and this method has been progressively modified to improve exposure and safety. Because we are able to visualize the sella without a sublabial incision or septal resection, we have nearly eliminated the need for nasal packing, reduced the average hospital stay to 2.5 days, and improved patient satisfaction.

Transnasal endoscopic approach to the sella turcica

The transseptal/transsphenoidal approach to the pituitary gland has been the most commonly used approach for resection of pituitary adenomas for the last 50 years. This procedure has a low morbidity and provides direct midline access to the sella and pituitary gland. Recent advancements in endoscopic surgery, however, suggest that a lower morbidity approach to the sella would be possible via transnasal endoscopic route. Prior reports have confirmed effectiveness of this approach to the pituitary gland and we report here an early series of endoscopic transnasal pituitary surgery from our institution. We report seven cases of transnasal endoscopic pituitary surgery. Our technique consists of endoscopic exposure of the sphenoid ostium unilaterally, excision of the posterior septum anterior to the rostrum of the sphenoid sinus with resection of the sphenoid rostrum for bilateral exposure of the sphenoid sinus. A specially designed nasal speculum is positioned to displace the posterior septum and lateralize the middle turbinates, permitting direct midline exposure of the sphenoid sinus and sella. We have progressively modified the technique over the seven cases that we present and will discuss our specific instrumentation, indications, and technique for this procedure. We have encountered one cerebrospinal fluid leak in this series. Patient satisfaction has been high and hospitalization is less than with the conventional transseptal approach, averaging 1 day. Our impression is that the transnasal endoscopic approach to pituitary adenomas is a safe technique with reduced morbidity permitting shortened hospital stay.

Endoscopic sphenoidotomy approach to the sella

OBJECTIVE

Advances in optics, miniaturization, and endoscopic instrumentation have revolutionized surgery in the past decade. We report our experience with the endoscope in nine patients with sellar lesions who underwent an endoscopic sphenoidotomy approach to the sella.

METHODS

An endoscopic transnasal cavity sphenoidotomy approach without a septal dissection was used in the resection of pituitary adenomas and other sellar lesions.

RESULTS

This approach provided excellent exposure of the sella and adequate working space. The technique produces less postoperative pain and, in some cases, shortens hospital stay. The sphenoidotomy approach eliminates the problems of lip numbness, septal perforations, and oronasal fistulas.

CONCLUSION

The endoscopic sphenoidotomy approach has become our preferred approach to sellar lesions.

Endoscopic endonasal transsphenoidal surgery: experience with 50 patients

An endoscope was used in transsphenoidal surgery and eventually replaced the operating microscope as the tool for visualization. This study focuses on 50 patients (28 females and 22 males) with a median age of 38 years (range 14-88 years). Initially, four patients underwent operation via a sublabial-transseptal approach using a rigid endoscope in conjunction with an operating microscope. The 48 subsequent operations were performed through a nostril using only rigid endoscopes. Forty-four patients had pituitary adenomas and six had various other lesions. Thirteen patients had microadenomas, 16 had intrasellar macroadenomas, nine had macroadenomas with suprasellar extension, and six had invasive macroadenomas involving the cavernous sinus. Seven patients had recurrent pituitary adenomas and 25 had hormone-secreting adenomas (eight patients with Cushing's disease and 17 patients with prolactinomas). Among the eight patients with Cushing's disease, seven had resolution of hypercortisolism clinically and chemically. Of the 17 patients with prolactinomas, 10 improved clinically with normal serum prolactin levels, four improved clinically with elevated serum prolactin levels, and three had residual tumors in the cavernous sinus. Among the 19 patients with nonsecreting adenomas, 16 underwent total resection and three subtotal resection leaving residual tumor in the cavernous sinus. Postoperatively, all patients who had undergone endonasal endoscopic surgery had unobstructed nasal airways with minimal discomfort. More than half of the patients required only an overnight hospitalization.

Endoscopic pituitary surgery: an early experience

BACKGROUND

As an element of a minimally invasive management approach, we had developed an endonasal endoscopic transsphenoidal technique for the treatment of pituitary tumors. Initially, four patients were operated on via a sublabial, transseptal approach using a fiberoptic rigid endoscope in conjunction with the operating microscope. Encouraged by that experience, our subsequent 11 patients had undergone endonasal endoscopic transsphenoidal surgery without the use of a retractor or speculum.

METHODS

Our group of patients included nine females and six males, with an age range of 17-88 years (median: 43 years). There were four microadenomas, four intrasellar macroadenomas, three macroadenomas with suprasellar extension, three invasive macroadenomas involving the cavernous sinus with suprasellar extension, and one metastatic adenocarcinoma.

RESULTS

Thirteen patients with pituitary adenomas experienced resolution of their symptoms postoperatively. One patient with a recurrent prolactinoma responded partially following surgery and subsequently underwent gamma knife radiosurgery. Two patients were treated with postoperative fractionated radiation therapy, one for residual pituitary adenoma in the cavernous sinus, and the other for metastatic adenocarcinoma, respectively. The first patient, treated via an endonasal endoscopic approach for biopsy of the metastatic adenocarcinoma, developed postoperative cerebrospinal fluid (CSF) leak that was successfully managed with endoscopic packing of a fat graft.

CONCLUSIONS

The endonasal endoscopic transsphenoidal approach facilitates faster postoperative recovery by the avoidance of traditional incision and postoperative nasal packing. It offers a panoramic view of the sphenoid sinus and excellent visualization of the sellar and suprasellar structures with increased illumination and magnification. Such visualization provides the potential for more complete tumor resection, as well as a better chance of preserving pituitary function and avoiding neurovascular injury.

Transnasal endoscopic surgery of the pituitary gland: technical note

OBJECTIVE

An approach to transnasal transsphenoidal debulking of pituitary tumors using endoscopic guidance is presented.

METHODS

Technical details of this approach using an endoscope inserted through one nostril and operating instruments inserted through a submucosal tunnel created via the other nostril are discussed.

RESULTS

Ten patients who had operations are tabulated. Illustrative cases are presented.

CONCLUSION

Endoscopic debulking of pituitary tumors can provide good results with minimal operative morbidity.

Endoscopy assisted transsphenoidal surgery for pituitary adenoma. Technical note

Inspired by an experience with endoscopic paranasal sinus surgery, an endoscope was applied in transsphenoidal pituitary surgery. This endoscopic transsphenoidal technique has been used in 45 cases of pituitary adenomas. Using a 4 mm rigid endoscope, the pituitary adenoma is removed through a nostril. A zero-degree endoscope is used for micro-adenomas. A combination of a 0-degree endoscope and a 30-degree endoscope is used for macro-adenomas that have extended to the suprasellar region. Although it is early in our experience with a small number of patients, the short-term surgical results have been encouraging with patients' short hospital stay and minimum morbidity. The endoscopic technique that has evolved with our experience is described with two cases of pituitary adenomas.